1. Field of the Invention
The present invention relates to equipment used for mechanical treatment of disperse materials and more particularly to grinding aimed at obtaining finely dispersed powders, suspensions, emulsions and pastes.
2. Description of the Prior Art
At present disintigration of hard materials is accomplished by means of most widely used ball mills comprising a revolving drum partially filled with freely moving grinding media such as spherical bodies (balls) or of other shapes, and a material subject to grinding (cf. Equipment for Plants of Paint and Varnish Industry by Gorlovsky N. A., Kozulin N. A., Publishing House "Khimya", 1980, Leningrad, p.p. 158-161).
At the present time the potential of ball mills have mainly been exhausted. This is explained by the fact that power intensity of the grinding process cannot be substantially increased. Moreover, the grinding media act on a raw product stochastically which manifests itself in a substantial number of idle impacts of the grinding bodies with one another and with walls of the drum. Therefore the ball mills are very cumbersome, operate with a substantial noise, consume a great amount of power and provide a low specific output.
Further improvement of the mills is associated with increase in the power intensity of the grinding process and with the improvement of the crushing mechanism. As a practical embodiment of the above-mentioned trends in improvement of the mills, there is presented a vibratory grinding of the effectiveness of which amounts to increase in the number of impacts of the grinding bodies with one another and with walls of a grinding chamber (cf. Mechanical Equipment of Enterprises Producing Building Materials, Articles and Constructions by Bauman V. A. et al, Publishing House "Mashinostroenie", Moscow, 1981, p.p. 130-132). However, the vibratory mills are complex in design, operate with a substantial noise, transmit vibrations to the environment, have supporting bearings with a short service life, fail to be fed with lumpy material and consume much power. The grinding process of these machines is characterized by the most pronounced cyclic action.
Evolution in the development of the grinding technique has led to production of planetary mills (cf. Equipment for Plants of Paint and Varnish Industry by Gorlovsky N. A., Kozulin N. A., Published House "Khimya", Leningrad, 1980, p.p. 158-161) which are essentially drums moving along planetary trajectories and internally accommodating grinding bodies. Featuring, on the whole, a substantially high intensity of the grinding process, the planetary mills by their technical and economic indices have to specific advantages over the vibratory mills, but are more complex in design.
Widely known in the prior art are impact mills in which the working members are operating at increased speeds and of which may be singled out disintegrators comprising two discs rotating in opposite directions and provided with grinding bodies in the form of bars (cf. Mechanical Equipment of Interprises Producing Building Materials, Articles and Constructions by Bauman V. A. et al, Publishing House "Mashinostroenie", Moscow, 1981, p.p. 128-129). A relative peripheral velocity of the bars is substantially high and amounts to 200-250 m/s of which causes their rapid wear and prevents the desintegrators from being used for treatment of materials having Mohs' hardness over 4 and containing no large hard inclusions.
Well known to the prior art are crushing apparatus, for example, roll mills in which the crushing members are presented by revolving rolls (cf. Equipment for Plants of Paint and Varnish Industry by Gorlovsky N. A., Kozulin N. A., Publishing House "Khimya", Leningrad, 1980, p.p. 319-321). However these mills have a small number of crushing zones, fail to provide fine and extra fine crushing and also due to the fact that the material slips over the surface of the rolls the roll mills are not suitable for crushing abrasive materials.